In an automated fabrication plant setting (commonly referred to as “fab”), wafers are contained in a wafer carrier which is transported between stations via an automated material handling system (AMHS). A station could be a process tool to deposit or to etch films, or a metrology tool to measure characteristics of the films. A wafer carrier in an automated fab is also known as a front opening unified pod and is commonly referred to as a FOUP. A FOUP is typically formed of a specialized plastic housing, which is designed to hold semiconductor wafers securely and safely in a protective environment. A FOUP includes a front opening section which allows the wafers to be inserted therein and removed therefrom for processing.
A significant amount of time can be incurred in transporting the FOUP from station to station, particularly if the automated fabrication plant is large or if there are numerous steps in completing the manufacturing process. Typically, after processing the wafer at a station, the FOUP including the processed wafers, are transported to a metrology station for measurement. Often, after further transporting and processing of the wafers at each subsequent station, the FOUP is transported to the metrology station for further measurement. Additionally, metrology equipment is expensive and occupies cleanroom floor space.